Ruby中数组散列的所有可能组合 [英] All possible combinations from a hash of arrays in Ruby

问题描述

我有什么：

假设我有这样的散列，各种值都属于一个参数。

  a = {} 
a [：bitrate] = [100，500，1000] 
a [：fps] = [ 15，30] 
a [：qp] = [20，30] 
  

---

我需要：

我需要一些方法来迭代获取所有这些值的可能组合，所以，所有的参数/值对：

• bitrate = 100 ， fps = 15 ， qp = 20


• bitrate = 500 ， fps = 15 ， qp = 30


• ...

参数的数量（即键）和值的数量（即值数组的长度）事先不知道。理想情况下，我会这样做：

  a.foo do | ret | 
 puts ret.keys＃=> [bitrate，fps，qp] 
 puts ret.values＃=> [100，15，20] 
结束
  

...其中块被称为每个可能的组合。我如何定义 foo ？

---

不需要：

现在，我知道这一点：组合数组数组进入所有可能的组合，仅在Ruby中转发，提示如下：

  a.first.product（* a [1 ..- 1]）。map（&：join）
  

值和数组只在数组中，并且我需要对参数名称的原始引用。

解决方案

  a = {} 
a [：bitrate] = [100，500，1000] 
a [：fps] = [15，30] 
a [：qp] = [20，30] 
 
 def product_hash（hsh）
 attrs = hsh.values 
 keys = hsh.keys 
 product = attrs [0] .product（* attrs [1 ..- 1]）$ ​​b $ b product.map {| p | Hash [keys.zip p]} 
结束
 
 product_hash（a）
  

你会得到

  [{：bitrate =>100，：fps =>15 ，：qp =>20}，
 {：bitrate =>100，：fps =>15，：qp =>30 ：比特率=>100，：：fps =>30，：：qp =>20}，
 {：比特率=>100 ：：qp =>30}，
 {：bitrate =>500，：fps =>15，：qp =>20 bitrate =>500，：fps =>15，：：qp =>30}，
 {：bitrate =>500，：fps =>30 ：qp =>20}，
 {：比特率=>500，：fps =>30，：：qp =>30}，
 { =1000，：fps =>15，：：qp =>20}，
 {：bitrate =>1000，：fps =>15 qp => 30}，
 {：比特率=>1000，：fps =>30，：：qp =>20}，
 {：bitrate = >1000，：fps =>30，：：qp =>30}] 
  

您还可以将新密钥添加到散列中。

  a = {} 
a [：bitrate] = [100，500，1000] 
a [：fps] = [15，30] 
a [：qp] = [20，30] 
 a [：bw] = [true，false] 
 
 product_hash（a）
 
＃=> 
 [{：bitrate =>100，：fps =>15，：qp =>20，：bw => true}，
 {：bitrate => ;100，：：fps =>15，：：qp =>20，：bw => false}，
 {：bitrate =>100，：fps => 15：qp =30，：bw => true}，
 {：bitrate =>100，：fps =>15，：qp => 30，bw => false}，
 {：bitrate =>100，：fps =>30，：qp =>20，：bw => true} ，
 {：bitrate =>100，：fps =>30，：qp =>20，：bw => false}，
 {：bitrate => ;100，：：fps =>30，：qp =>30，：bw => true}，
 {：bitrate =>100，：fps => 30，：qp =>30，：bw => false}，
 {：bitrate =>500，：fps =>15，：qp => 20，：bw => true}，
 {：bitrate =>500，：fps =>15，：qp =>20，：bw => false} ，
 {：bitrate =>500，：fps =>15，：qp =>30，：bw => true}，
 {：bitrate => ;500，：fps =>15，：：qp =>30，：bw => false}，
 {：bitrate =>500，：fps => 30，：：qp =>20，：bw => true}，
 {：bitrate =>500，：fps =>30，：qp => 20，：bw => false}， 
 {：bitrate =>500，：fps =>30，：qp =>30，：bw => true}，
 {：bitrate => 500，：fps =>30，：qp =>30，：bw => false}，
 {：bitrate =>1000，：fps => 15，：：qp =>20，：：bw => true}，
 {：bitrate =>1000，：fps =>15，：qp =>20 ：bw => false}，
 {：bitrate =>1000，：fps =>15，：：qp =>30，：bw => true}， 
 {：bitrate =>1000，：fps =>15，：qp =>30，：bw => false}，
 {：bitrate => 1000，：fps =>30，：：qp =>20，：bw => true}，
 {：bitrate =>1000，：fps => 30：：qp =>20，：bw => false}，
 {：bitrate =>1000，：fps =>30，：qp =>30 ：bw => true}，
 {：bitrate =>1000，：fps =>30，：：qp =>30，：bw => false}] 
  

What I have:

Let's say I have a hash like this, with various values belonging to one parameter.

a = {}
a[:bitrate] = ["100", "500", "1000"]
a[:fps] = ["15", "30"]
a[:qp] = ["20", "30"]

---

What I need:

I need some way to iteratively get all the possible combinations of these values, so, with all the parameter/value pairs:

• bitrate = 100, fps = 15, qp = 20
• bitrate = 500, fps = 15, qp = 30
• ...

The number of parameters (i.e. the keys) and the number of values (i.e. the length of the value arrays) are not known beforehand. Ideally, I'd do something like:

a.foo do |ret|
  puts ret.keys   # => ["bitrate", "fps", "qp"]
  puts ret.values # => ["100", "15", "20"]
end

… where the block is called for each possible combination. How can I define foo?

---

What I (probably) don't need:

Now, I know this: Combine array of array into all possible combinations, forward only, in Ruby, suggesting something like:

a.first.product(*a[1..-1]).map(&:join)

But this operates on values and arrays in arrays only, and I need the original reference to the parameter's name.

解决方案

a = {}
a[:bitrate] = ["100", "500", "1000"]
a[:fps] = ["15", "30"]
a[:qp] = ["20", "30"]

def product_hash(hsh)
  attrs   = hsh.values
  keys    = hsh.keys
  product = attrs[0].product(*attrs[1..-1])
  product.map{ |p| Hash[keys.zip p] }
end

product_hash(a)

you'll get

[{:bitrate=>"100", :fps=>"15", :qp=>"20"},
 {:bitrate=>"100", :fps=>"15", :qp=>"30"},
 {:bitrate=>"100", :fps=>"30", :qp=>"20"},
 {:bitrate=>"100", :fps=>"30", :qp=>"30"},
 {:bitrate=>"500", :fps=>"15", :qp=>"20"},
 {:bitrate=>"500", :fps=>"15", :qp=>"30"},
 {:bitrate=>"500", :fps=>"30", :qp=>"20"},
 {:bitrate=>"500", :fps=>"30", :qp=>"30"},
 {:bitrate=>"1000", :fps=>"15", :qp=>"20"},
 {:bitrate=>"1000", :fps=>"15", :qp=>"30"},
 {:bitrate=>"1000", :fps=>"30", :qp=>"20"},
 {:bitrate=>"1000", :fps=>"30", :qp=>"30"}]

You can also add new key to your hash.

a = {}
a[:bitrate] = ["100", "500", "1000"]
a[:fps] = ["15", "30"]
a[:qp] = ["20", "30"]
a[:bw] = [true, false]

product_hash(a)

#=>
[{:bitrate=>"100", :fps=>"15", :qp=>"20", :bw=>true},
 {:bitrate=>"100", :fps=>"15", :qp=>"20", :bw=>false},
 {:bitrate=>"100", :fps=>"15", :qp=>"30", :bw=>true},
 {:bitrate=>"100", :fps=>"15", :qp=>"30", :bw=>false},
 {:bitrate=>"100", :fps=>"30", :qp=>"20", :bw=>true},
 {:bitrate=>"100", :fps=>"30", :qp=>"20", :bw=>false},
 {:bitrate=>"100", :fps=>"30", :qp=>"30", :bw=>true},
 {:bitrate=>"100", :fps=>"30", :qp=>"30", :bw=>false},
 {:bitrate=>"500", :fps=>"15", :qp=>"20", :bw=>true},
 {:bitrate=>"500", :fps=>"15", :qp=>"20", :bw=>false},
 {:bitrate=>"500", :fps=>"15", :qp=>"30", :bw=>true},
 {:bitrate=>"500", :fps=>"15", :qp=>"30", :bw=>false},
 {:bitrate=>"500", :fps=>"30", :qp=>"20", :bw=>true},
 {:bitrate=>"500", :fps=>"30", :qp=>"20", :bw=>false},
 {:bitrate=>"500", :fps=>"30", :qp=>"30", :bw=>true},
 {:bitrate=>"500", :fps=>"30", :qp=>"30", :bw=>false},
 {:bitrate=>"1000", :fps=>"15", :qp=>"20", :bw=>true},
 {:bitrate=>"1000", :fps=>"15", :qp=>"20", :bw=>false},
 {:bitrate=>"1000", :fps=>"15", :qp=>"30", :bw=>true},
 {:bitrate=>"1000", :fps=>"15", :qp=>"30", :bw=>false},
 {:bitrate=>"1000", :fps=>"30", :qp=>"20", :bw=>true},
 {:bitrate=>"1000", :fps=>"30", :qp=>"20", :bw=>false},
 {:bitrate=>"1000", :fps=>"30", :qp=>"30", :bw=>true},
 {:bitrate=>"1000", :fps=>"30", :qp=>"30", :bw=>false}]

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